Upper saw-guide.



F. L. WALKER & H. G. DITTBENNER.

UPPER SAW GUHJE.

APPLICATION FILED APR. 5 1916.

1,260,837. Patented Mar. 26, 1918.

3 SHEETS-SHEET 1.

Fig.1

Mam

F. L. WALKER & H. G. DITTBENNER. UPPER SAW GUIDE.

APFUCATXON FILED APR. 5. 1525. 1,260,837. Patented Mar. 26, 1918.

3 SHEETS-SHE 2.

F. L. WALKER & Hx G. DITTBENNER.

UPPER SAW GUHJE.

AEPLHQA'HBN FILED APPLE. Wm

[260,837. Patented Mar. 26, 1918.

3 SHEEIS SiIiET 3.

UNITED STATESIPATENT OFFICE.

FLETCHER L. WALKER AND HERMANN G. m'rwnnnnnn, 0F manna Poms. Mmvnso'm.

UPPER SAW-GUIDE.

To all whom it may concern:

Be it known that we, FLn'ronnn L. lVALiinn and Humans Ur. IJITTBENNER, citizens oitthe United States; residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain .new and useful Improvements in Upper Saw-Guides; and we do hereby declare the following tube a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

Our present invention relates to band saw mills and has for its object to provide crrtain improvements in and means for adjust ing and regulating the upper saw guide.

Generally stated, the invention consists of the novel devices and combinations of devices hereinafter described and. defined in the claims.

In the accompanying drawings which villustrate the invention, like characters in dicate like parts throughout the several views.

Referring to the drawings:

Figure. l is a side elevation showing a .hand saw mill having the several features of our invention apphed thereto, the lower portion of the mill being broken away;

Fig. 2 is a front elevation of the parts shown in Fig. 1;

Fig. 3 is a front elevation of the saw guide removed from the machine;

. Fig. 4 is a view of the parts shown in Fig. 3, partly in plan and partly in horizontal section; Fig. 5 is an enlarged section taken on the line as W of Fig. 3, some parts bein broken away; and

Fig. 1 is a detail in section showing one of the automatic take-up wedges. Y

Of the parts of the band saw mill. the nu meral 1 indicates the band saw, the numeral -2 the upper band saw wheel, the numeral. 3.

the vertically adjustable columns having the enston'iary hearings in which the shaft 4 of the wheel 2 is journaled, and the nu:

meral 5 indicates the laterally spaced brackets. 111 which the columns?! fll'tflllfilllltedatfl move vertically. One of the brackets 5 is provided with annpwardljr extended arm 6 and a. depending shoe guide 7. r

I Thegnide Shoe 8 which carriesthe upper sawlgulde, embraces and is mounted to slide Specification of Letters Patent.

vertically on a flange of the shoe guide 7. 56 and this llange is provided with rat t Patented Mar. 2a, 1918.

Application filed April 5, 1916. Serial No. 89,046.

teeth 9 for an important purpose which will presently a pear. Play, dueto wear between the s we 8 andguide'T, is-taken up automatically by a plurality of springpressed wedges 10. seated in the hack of the shoe and engaging a wear plate 1"]. that is movably mounted in the saidshoe and directly engages the back of the flanges of the guide 7. r i

The guide shoe 8, at its upper portion, is provided with heavy horizontally'projecting parallel studsylz on which the upper ends of depending parallel links 13 are pivotally mounted. The jaws or jaw plates H and 1:3 of the saw guide are pivotally supported for horizontal swinging movements b" the lower ends of these parallel links 125, and, as shown, this is accomplished by a novel means, the preferred arrangement of which is, as follows:

At. their extreme lower ends, the said links 13 are l'ormedwilh sleeve-like heads 16 in which gudgmms' 17 are mounted for. rota r and endwise sliding movements. The sliding movements of the said gndgeons are imparted by adjusting screws 18 having threaded engagement. therewith and swiveled at 19 to head plates :20 that are rigidly but detachably secured to the s eeves 16. These screws. as illustrated, hr. re the same threads, but at. their outer ends, they are provided with splocket'wheels21 and 22, the latter of which is twice. the diameter of the former. A sprocket chain 23 runs over the alined sprockets 21 and 22. Theplojecting axis of the screw 18 having the small procket 21 is twice as far as is the projected axis of the other screw, from a point marked a on Fig. 4., and which point is between the extended saw-guiding ends of the jaws, and at approximately the transverse center of the guide saw 1. This relation of the parts is important, as will he hereinafter made clear.

Theprojecting ends of the gufdg eons 17 100 to a centering plate 25'. Fdrther'n-iore, the 105 two aw plates 14 and 15 are provided with inter upping lugs that are pivoted on the pin 24 t at is nearestto the saw, so that the two jaws open and'close' on the said pivot in. At their saw-embracing ends, the jaw 110 shown in Figs. 4 and lates 14 are provided with the customary wooden guide plugs 26 that directly engage the sides of the saw. The other ends of the said jaw plates 14 and 15 are subject to a spring device that tends to yieldingly; draw the same together and to separate the pluguipped oisaw guidin ends of said jaw p ates. This'spring device, as shown, comprises a bolt 27 passed through perforations in said plates 14 and 15, and provided with a spring 28 compressed between said arms '14 and a nut 29 on said bolt. The right hand or outer end of the centering plate is beveled and the adjacent end portions of the jaw plates are heavily beveled, as best 5, and these beveled surfaces are normally engaged by a duplex wedge 30 that is rigidly but adjustably carried in a socket 31 formed in the free end of a wedge arm 32 that is carried. by and rigidly secured to one of the links.13. As shown, the wedge 30 is adapted to be adjusted by a screw 33 threaded in the top of the socket 31, and is adapted to be held where setby set screws 34 screwed into the sides of the said socket.

,The guide shoe 8, and the saw guide carried thereby, are arranged to be vertically adg'lusted in a well known manner, by a cylin or and piston engine. As shown, the cylinder 35 of this guide adjusting engine is rigidly secured to the bracket arm 6, and

its piston rod 36,91, its lower end, is attached to the upper portion of the said shoe 8. The means for controlling the reciprocating movements of the engine piston, and, consequentl of the guide shoe and saw guide, are wel known and need not here be further considered, except to state that by proper manipulation of the same, the said shoe and saw guide which are very heavy counterbalanced structures, maybe easily raised and lowered, at will.

The best sawing action is produced by having the saw guide located as close as practicable to the upper guide wheel 2, and yet, as, of course, will be understood, serious damage to the saw and other mechanism is produced if the saw guide were permitted to run into the upper saw wheel. To avoid this, I provide an automatic shoe lock, of which, in the preferred construction, the ratchet teeth 9 on the saw guide 7 is a oooperating element.

For cooperation with the said ratchet teeth, the shoe 8 is provided with a springretracted lock dog 37, which, at one end, has a projecting arm 38 arranged to engage a stop 39. This stop 39 is in the form of a" strong spring arm, one end of which is socured, as shown, to the yoke portion of one of the vertically movable columns 3, so that it always bears a predetermined osition, in respect to the upper saw wheel. he said stop may take various forms and be applied in diflerent ways, but it must bear a constant or known, predetermined relation to the upper saw wheel and which partake of the vertical adjustments thereof. With this automatic lock, the uide shoe and saw guide may be freely adjusted vertically, but when moved upward so that the saw guiding ends of the jaws too closely approach the upper saw wheel, the arms 38 will strike the stop 39 and force the lock do 37 into engagement with one of the rate et teeth 9, thereby positively locking the said shoe and saw guide so that they cannot be moved farther upward. It may sometimes ha pen that the free. end of the 'arm 38 'wi be forced above the stop 39 before the dog has been engaged with a ratchet tooth, in which. case, the said stop will yield to permit such movement, and, ofcourse, the said arm will pass freely over the stop under downward movement. -As soon as the shoe and guide are again lowered, the lock dog will be automatically retracted by its spring so that upward and downward movements of the saw guide below theextreme upper position noted, will be freely accomplished by manipulation of the adjusting engine. This automatic saw guide lock constitutes an important feature of the present invention.

It is, of course, a well known fact that the toothed-edge of a band saw, because of the set of the teeth, is much thicker than the bodyof the saw. It frequently happens thatin making the first cut-off from a log, the operator will not correctly judge the size of the log, and hence, will not raise the saw guide sufiiciently to clear the log, and in this case, the said log, moving in a direction from left toward the right, in respect toFig, 2, will strike the en a of the saw guiding jaws 14 and 15 and orce the same toward the -right, under which movement, the jaws will be raised, while maintained in a horizontal position, until the clear the log. With a double edge ban saw, such movement of the jaws would cause the rear teeth of the band saw to cut away the sawengaging faces of the wooden guide plugs, so that when they are again forced back to working position on the saw, there will be too great play between the same and the saw. With this construction described,

however, the-initialreceding movement of the jaws 14 and 15 and supporting links 13 raises the arm 32, and carries the duplex wed e 30 from between the beveled surfaces of t c said jaws and centering plate 25, and the spring 28 then instantly separates the plug-equipped ends of the ewe so that the plugs wil not be cut by t e rear teeth of the band saw. The band saw shown is a two-way saw, that is, a saw havin teeth on both edges, and the device just described is especial] adapted for use 111 connection therewith, ut, nevertheless. it is dem 'ra c,

the saw.

' saw,'because the one 9 even when used on a one-wt saw, that is,

a saw having teeth on one e go only.

After the saw guide has been displaced, as stated, it can easily be restored, by again pressing the same ownward and toward the saw, under which movement to normal position, the duplex wedge again engages the beveled surfaces of the jaws and centering plates, overcomes the spring 28, and restoresthe guide plugs to normal action on It will frequently hagpeln that a band ge-, 1:h'er mf is of greater length than the. other sawing, will tend to lead toward one slde or the other, and thus cut a tapered board. This tendency of the saw tolead or drift toward one side, may be overcome by setting the saw guide to lead slightly in the opposite direction, or so that it will cut straight. Such adjustments are'arran I to be given to the saw guide, that is, to t 'e jaws or jaw plates thereof, by the mechanism best shown in Fig. 4 and which mechanism includes the before described screws 18, and may be well designated as a saw lead adjuster.

By the described arrangement of the said parts, the two gudgeons 17 will be' van a differential movemenhso that when a justed horizontally the two 'awlplates 14 and 15 will be moved iv'ota y on the point a before noted. 0t erwise stated, the screw 18, at the right, will rotate twice as fast as the screw at the left, and, consequently, the right hand gudgeon 17 will be given twice as much axial movement as the left hand dgeon, and, as the right hand gudgeon is t iiice as far as the left hand dgeon from the point a, it is evident that t e aw plates will be given an oscillatory movement around the point a as a pivot oint. Very sli ht movement of the said p ates will be su cient to correct the lead of the saw in the most extreme cases. i

It will be understood that means for automatically taking up the play between the shoe and. e 1s very important, because, -even s ght play between these parts would permit the saw guide to shift materially from its proper working position. The angle of the automatictakeup wedges should be such that they cannot be pressed backward by pressure a plied laterally to the same from the shoe. therwise stated, they will automatically take up play but cannot he accidentally forced in a reverse direction" or made to give back the play once taken up.

. What we claim is:

1. In a band saw mil the combination with a saw guidin wheel that is adjustable for band saws of dlfi'erent le s, of a shoe adjustable independently of t e adjustment of the wheel in a direction parallel to the line of adjustment thereof, means tar thus adjusting said shoe, :1 saw guide carried by said shoe, an automatic lock limiting the movement of said shoe in a direction to carry said saw guide toward said wheel, and a lock actuating stop adjustable with said wheel.

2. In a band saw mill, the combination with a wheel that is adjustable for band saws of different lengths, of a relatively fixed shoe guide having ratchet teeth, a guide shoe slidable on said shoe guide, means for moving said shoe uide, a saw guide carried by said shoe guide, a yieldingly retracted lock dog carried by said shoe, and a dog actuating device adjustable with said wheel and operative to engage said do with said ratchet teeth to thereby limit' t e movement of said saw guide toward said wheel.

3. In a band saw mill, the combination with vertically movable columns, of an upper saw wheel adjustable with said columns for band saws of different lengths, a relatively fixed shoe guide having ratchet teeth, means for adjusting said shoe vertically, a saw guide carried by said shoe, a ieldingly retracted lock dog carried by sai shoe and provided with a projecting arm, and a do actuating element carried by one of sai -'columns and operating on the arm of said dog to-enga e the latter with the ratchet teeth df'sai guide, to thereby automatically limit the movements of said saw guide toward said upper saw wheel.

4. In a band saw mill, the combination with saw guiding jaws mounted for upward receding movements, means for normally holding said jaws operative to guide the band saw, and means for automatically sep arating the saw guiding ends of said jaws when the latter are given receding movement.

5. In a band saw mill, the combination with the upper wheel and band saw, of a link support, links pivoted to said support saw guiding jaws carried by the free an s of said inks, yielding means tendin to separate the saw guiding ends of said aws, and

a wedge device carried by one of the said links, normally en aging said jaws and holding the saw gui ing ends thereof operative to guide the same, the swinging movement of said link and receding movement of saidjaws servin to retract said wedge device and permit c said yielding means to separate the saw guiding ends of said aws.

6. In a band saw mill, the combination with the upper saw wheel and band saw, of a link support, links pivoted to said support at their upper ends, jaws pivoted to the lower ends of said links, a spring device tending to hold the projecting ends of said jaws operative to jaws at their other ends having wedge engaging surfaces, at centering plate located between said jaws and fixed against lateral movements but partaking of the other movements of said 'aws, an arm ri idly secured to one of the inks and proviged with a duplex wedge normally engaging said centering plate and the Wedge surfaces of said jaws and holding the saw guiding ends of said jaws operative to guide the saw, but which wedge is retracted by an initial receding movement of said jaws and links from normal positions.

In testimon whereof I aiiix my signature 1n presence 0 two witnesses.

FLETCHER L. WALKER. Witnesses:

R. FCPRAY, MABEL E. ABRAHAM. In testimon whereof I aflix my signature in presence 0 two witnesses.

HERMANN G. DITTBENNER. Witnesses:

HARRY D. KILGORE, FRANK D. MERCHANT. 

